﻿#region  文件信息
// ---------------------------------------------------------------------------------------
// <copyright file="Class1.cs" company="">
// 作者：李帅伦
// </copyright>
// <summary>
// 类型简介：
// 类型详细：Class1.cs
// 创建时间：2014-12-11 14:24
// 修改时间：2014-12-11 14:24
// </summary>
// ---------------------------------------------------------------------------------------
#endregion

namespace WebCommon
{
    using System;
    using System.Drawing;

    /// <summary>
    /// 验证码
    /// </summary>
    public class VerifyCodeImage
        {
            public VerifyCodeImage()
            {
            }

            #region 验证码长度(默认4个验证码的长度)
            int length = 4;
            public int Length
            {
                get { return this.length; }
                set { this.length = value; }
            }
            #endregion

            #region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
            int fontSize = 50;
            public int FontSize
            {
                get { return this.fontSize; }
                set { this.fontSize = value; }
            }
            #endregion

            #region 边框补(默认1像素)
            int padding = 2;
            public int Padding
            {
                get { return this.padding; }
                set { this.padding = value; }
            }
            #endregion

            #region 是否输出燥点(默认不输出)
            bool chaos = true;
            public bool Chaos
            {
                get { return this.chaos; }
                set { this.chaos = value; }
            }
            #endregion

            #region 输出燥点的颜色(默认灰色)
            Color chaosColor = Color.LightGray;
            public Color ChaosColor
            {
                get { return this.chaosColor; }
                set { this.chaosColor = value; }
            }
            #endregion

            #region 自定义背景色(默认白色)
            Color backgroundColor = Color.White;
            public Color BackgroundColor
            {
                get { return this.backgroundColor; }
                set { this.backgroundColor = value; }
            }
            #endregion

            #region 自定义随机颜色数组
            Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
              Color[] Colors
            {
                get { return this.colors; }
                 
            }
            #endregion

            #region 自定义字体数组
            string[] fonts = { "Arial", "Georgia" };
              string[] Fonts
            {
                get { return this.fonts; }
                 
            }
            #endregion

          

            #region 产生波形滤镜效果
            //private const double PI = 3.1415926535897932384626433832795;
            private const double PI2 = 6.283185307179586476925286766559;
            /// <summary>
            /// 正弦曲线Wave扭曲图片（Edit By 51aspx.com）
            /// </summary>
            /// <param name="srcBmp">图片路径</param>
            /// <param name="bXDir">如果扭曲则选择为True</param>
            
            /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
            /// <returns></returns>
              System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
            {
                System.Drawing.Bitmap bitmap = new Bitmap(srcBmp.Width, srcBmp.Height);

                // 将位图背景填充为白色
                System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(bitmap);
                graphics.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, bitmap.Width, bitmap.Height);
                graphics.Dispose();

                double dBaseAxisLen = bXDir ? (double)bitmap.Height : (double)bitmap.Width;

                for (int i = 0; i < bitmap.Width; i++)
                {
                    for (int j = 0; j < bitmap.Height; j++)
                    {
                        double dx = 0;
                        dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen;
                        dx += dPhase;
                        double dy = Math.Sin(dx);

                        // 取得当前点的颜色
                        int nOldX = 0, nOldY = 0;
                        nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
                        nOldY = bXDir ? j : j + (int)(dy * dMultValue);

                        System.Drawing.Color color = srcBmp.GetPixel(i, j);
                        if (nOldX >= 0 && nOldX < bitmap.Width
                         && nOldY >= 0 && nOldY < bitmap.Height)
                        {
                            bitmap.SetPixel(nOldX, nOldY, color);
                        }
                    }
                }
                return bitmap;
            }
            #endregion

            #region 生成校验码图片
            public Bitmap CreateImage(string code, double multValue)
            {
                int fSize = this.FontSize;
                int fWidth = fSize + this.Padding;

                int imageWidth = (int)(code.Length * fWidth) + 4 + this.Padding * 2;
                int imageHeight = fSize * 2 + this.Padding;

                System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(imageWidth, imageHeight);

                Graphics graphics = Graphics.FromImage(bitmap);

                graphics.Clear(this.BackgroundColor);

                Random rand = new Random();

                // 给背景添加随机生成的燥点
                if (this.Chaos)
                {

                    Pen pen = new Pen(this.ChaosColor, 0);
                    int c = this.Length * 10;

                    for (int i = 0; i < c; i++)
                    {
                        int x = rand.Next(bitmap.Width);
                        int y = rand.Next(bitmap.Height);

                        graphics.DrawRectangle(pen, x, y, 1, 1);
                    }
                }

                int left = 0, top = 0, top1 = 1, top2 = 1;

                int n1 = (imageHeight - this.FontSize - this.Padding * 2);
                int n2 = n1 / 4;
                top1 = n2;
                top2 = n2 * 2;

                Font font;
                Brush brush;

                int cindex, findex;

                // 随机字体和颜色的验证码字符
                for (int i = 0; i < code.Length; i++)
                {
                    cindex = rand.Next(this.Colors.Length - 1);
                    findex = rand.Next(this.Fonts.Length - 1);

                    font = new System.Drawing.Font(this.Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
                    brush = new System.Drawing.SolidBrush(this.Colors[cindex]);

                    if (i % 2 == 1)
                    {
                        top = top2;
                    }
                    else
                    {
                        top = top1;
                    }

                    left = i * fWidth;

                    graphics.DrawString(code.Substring(i, 1), font, brush, left, top);
                }

                // 画一个边框 边框颜色为Color.Gainsboro
                graphics.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, bitmap.Width - 1, bitmap.Height - 1);
                graphics.Dispose();

                // 产生波形
                bitmap = this.TwistImage(bitmap, true, multValue, 4);

                return bitmap;
            }
        
          
            /// <summary>
            /// 将创建好的图片输出到页面
            /// </summary>
            /// <param name="code">验证码</param>
           
            public byte[] CreateImageOnPage(string code)
            {
                if (code == null)
                {
                    throw new ArgumentNullException("code");
                }
                using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream())
                {
                    using (Bitmap bitmap = this.CreateImage(code, 1))
                    {
                        bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                        return memoryStream.GetBuffer();
                    }
                }
            }

        #endregion
        }
 
}